The following invention relates to a rotating platen member for a printer.
More particularly, though not exclusively, the invention relates to a rotating platen member incorporating a platen surface, a capping device and a test print blotter for an A4 pagewidth drop on demand printhead in a printer.
The overall design of a printer in which the rotating platen member can be utilized revolves around the use of replaceable printhead modules in an array approximately 8 inches (20 cm) long. An advantage of such a system is the ability to easily remove and replace any defective modules in a printhead array. This would eliminate having to scrap an entire printhead if only one chip is defective.
A printhead module in such a printer can be comprised of a xe2x80x9cMemjetxe2x80x9d chip, being a chip having mounted thereon a vast number of thermo-actuators in micro-mechanics and micro-electromechanical systems (MEMS). Such actuators might be those as disclosed in U.S. Pat. No. 6,044,646 to the present applicant, however, there might be other MEMS print chips.
The printhead, being the environment within which the rotating platen member of the present invention is to be situated, might typically have six ink chambers and be capable of printing four color process (CMYK) as well as infra-red ink and fixative. An air pump would supply filtered air to the printhead, which could be used to keep foreign particles away from its ink nozzles. The printhead module is typically to be connected to a replaceable cassette which contains the ink supply and an air filter.
Each printhead module receives ink via a distribution molding that transfers the ink. Typically, ten modules butt together to form a complete eight inch printhead assembly suitable for printing A4 paper without the need for scanning movement of the printhead across the paper width.
The printheads themselves are modular, so complete eight inch printhead arrays can be configured to form printheads of arbitrary width.
Additionally, a second printhead assembly can be mounted on the opposite side of a paper feed path to enable double-sided high speed printing.
Various methods, systems and apparatus relating to the present invention are disclosed in the following co-pending applications filed by the applicant or assignee of the present invention simultaneously with the present application:
PCT/AU00/00518, PCT/AU00/00519, PCT/AU00/00520, PCT/AU00/00521, PCT/AU00/60522, PCT/AU00/00523, PCT/AU00/00524, PCT/AU00/00525, PCT/AU00/00526, PCT/AU00/00527, PCT/AU00/00528, PCT/AU00/00529, PCT/AU00/00530, PCT/AU00/00531, PCT/AU00/00532, PCT/AU00/00533, PCT/AU00/00534, PCT/AU00/00535, PCT/AU00/00536, PCT/AU00/00537, PCT/AU00/00538, PCT/AU00/00539, PCT/AU00/00540, PCT/AU00/00541, PCT/AU00/00542, PCT/AU00/00543, PCT/AU00/00544, PCT/AU00/00545, PCT/AU00/00547, PCT/AU00/00546, PCT/AU00/00554, PCT/AU00/00556, PCT/AU00/00557, PCT/AU00/00558, PCT/AU00/00559, PCT/AU00/00560, PCT/AU00/00561, PCT/AU00/00562, PCT/AU00/00563, PCT/AU00/00564, PCT/AU00/00565, PCT/AU00/00566, PCT/AU00/00567, PCT/AU00/00568, PCT/AU00/00569, PCT/AU00/00570, PCT/AU00/00571, PCT/AU00/00572, PCT/AU00/00573, PCT/AU00/00574, PCT/AU00/00575, PCT/AU00/00576, PCT/AU00/00577, PCT/AU00/00578, PCT/AU00/00579, PCT/AU00/00581, PCT/AU00/00580, PCT/AU00/00582, PCT/AU00/00587, PCT/AU00/00588, PCT/AU00/00589, PCT/AU00/00583, PCT/AU00/00593, PCT/AU00/00590, PCT/AU00/00591, PCT/AU00/00592, PCT/AU00/00584, PCT/AU00/00585, PCT/AU00/00586, PCT/AU00/00594, PCT/AU00/00595, PCT/AU00/00596, PCT/AU00/00597, PCT/AU00/00598, PCT/AU00/00516, PCT/AU00/00517, PCT/AU00/00511, PCT/AU00/00501, PCT/AU00/00502, PCT/AU00/00503, PCT/AU00/00504, PCT/AU00/00505, PCT/AU00/00506, PCT/AU00/00507, PCT/AU00/00508, PCT/AU00/00509, PCT/AU00/00510, PCT/AU00/00512, PCT/AU00/00513, PCT/AU00/00514, PCT/AU00/00515
The disclosures of these co-pending applications are incorporated herein by cross-reference.
It is an object of the present invention to provide a rotating platen member incorporating a platen surface, a capping device and a test print blotter for a printer.
It is another object of the present invention to provide a rotating platen member incorporating a platen surface, a capping device and a test print blotter suitable for the pagewidth printhead assembly as broadly described herein.
It is another object of the present invention to provide a rotating platen member incorporating a platen surface, a capping device and a test print blotter for a printhead assembly on which there is mounted a plurality of print chips, each comprising a plurality of MEMS printing devices.
It is yet another object of the present invention to provide a method of rotating a platen member incorporating a platen surface, a capping device and a test print blotter in a printer without damaging the printing devices in the printer.
The present invention provides a platen assembly for a printer, comprising:
a chassis to which there is mounted a printhead,
a pair of bearing members supported by the chassis and movable toward and away from the printhead,
a body rotatably mounted between said bearing members, the body having a platen surface extending therealong and a capping device extending therealong, the platen surface and capping device being selectively aligned with the printhead upon rotation of the body from one angular orientation to another, and
means to move said bearing members toward and away from said printhead during said rotation of the body so that the body does not damage the printhead
Preferably the means to move said bearing members toward and away from said printhead comprise a pair of end caps upon the body, each end cap having a cam surface or surfaces that engage with a protrusion affixed to or formed integrally with the chassis.
Preferably the body also includes a blotting device exiling therealong.
Preferably the capping device and the blotting device are offset from one another by 120 degrees about the body.
Preferably the bearing members are bearing moldings, each riding upon one or more tracks affixed to the chassis.
Preferably the tracks are straight and parallel so as to allow linear movement of the bearing members and body toward and away from the printhead.
Preferably the bearing members are resiliently biased in a direction toward the printhead
Preferably the said resilient bias is by means of a spring ending between the respective bearing member and the chassis.
Preferably the body includes a flat portion forming a base for attachment of a capping member, the capping member having a capper house and capper seal member for sealing a nozzle guard of said printhead.
Preferably the blotting device includes a shaped body of blotting material housed with the body and including a part projecting through a longitudinal slot in the body to form an exposed blotting surface.
The present invention also provides a method of capping a printhead in a printer in which there is provided a chassis to which the printhead is mounted, the method comprising:
providing a selectively rotatable platen body alongside the printhead, which platen body includes a platen surface extending therealong and a capping device also extending therealong,
rotating the platen body from an orientation wherein the platen surface is aligned with the printhead to an orientation wherein the capping device is aligned with the printhead, and
causing movement of the platen body away firm the printhead during rotation thereof, such that the body does not damage the printhead during rotation
Preferably the method also serves to absorb ink during a test print phase, wherein said platen body also incorporates a blotting device extending therealong and the method includes rotating the platen body into a position wherein the blotting device is aligned with the printhead.
Preferably the method also includes the step of moving the platen body toward and/or away from the printhead during rotation thereof so at to bring said blotting device into alignment with said printhead.
As used herein, the term xe2x80x9cinkxe2x80x9d is intended to mean any fluid which flows through the printhead to be delivered to a sheet. The fluid may be one of many different coloured inks, infra-red ink, a fixative or the like.
A preferred foam of the present invention will now be described by way of example with reference to the accompanying drawings wherein:
FIG. 1 is a front perspective view of a print engine assembly
FIG. 2 is a rear perspective view of the print engine assembly of FIG. 1
FIG. 3 is an exploded perspective view of the print engine assembly of FIG. 1.
FIG. 4 is a schematic front perspective view of a printhead assembly.
FIG. 5 is a rear schematic perspective view of the printhead assembly of FIG. 4.
FIG. 6 is an exploded perspective illustration of the printhead assembly.
FIG. 7 is a cross-sectional end elevational view of the printhead assembly of FIGS. 4 to 6 with the section taken through the centre of the printhead.
FIG. 8 is a schematic cross-sectional end elevational view of the printhead assembly of FIGS. 4 to 6 taken near the left end of FIG. 4.
FIG. 9A is a schematic end elevational view of mounting of the print chip and nozzle guard in the laminated stack structure of the printhead
FIG. 9B is an enlarged end elevational cross section of FIG. 9A
FIG. 10 is an exploded perspective illustration of a printhead cover assembly.
FIG. 11 is a schematic perspective illustration of an ink distribution molding.
FIG. 12 is an exploded perspective illustration showing the layers forming part of a laminated ink distribution structure according to the present invention.
FIG. 13 is a stepped sectional view from above of the structure depicted in FIGS. 9A and 9B,
FIG. 14 is a stepped sectional view from below of the structure depicted in FIG. 13.
FIG. 15 is a schematic perspective illustration of a first laminate layer.
FIG. 16 is a schematic perspective illustration of a second laminate layer.
FIG. 17 is a schematic perspective illustration of a third laminate layer.
FIG. 18 is a schematic perspective illustration of a fourth laminate layer.
FIG. 19 is a schematic perspective illustration of a fifth laminate layer.
FIG. 20 is a perspective view of the air valve molding
FIG. 21 is a rear perspective view of the right hand end of the platen
FIG. 22 is a rear perspective view of the left hand end of the platen
FIG. 23 is an exploded view of the platen
FIG. 24 is transverse cross-sectional view of the platen
FIG. 25 is a front perspective view of the optical paper sensor arrangement
FIG. 26 is a schematic perspective illustration of a printhead assembly and ink limes attached to an ink reservoir cassette.
FIG. 27 is a partly exploded view of FIG. 26.